电机绝缘系统在高频冲击下局部放电试验研究

摘要

The measurement of partial discharge (PD) under high frequency impulse voltage may be effective to check the insulation condition of the motor insulation system.Depending on the sensor,there were two methods of detecting PD under high frequency voltage for the motor insulation system:High-frequency Current Transducer and ultrahigh frequency antenna.The PD activities mainly occur in both pulse rising edge and falling edge under the impulse voltage.The amplitudes of PD in both rising edge and falling edge were higher under the same applied voltage.In the qualification test of stator insulation system of wind turbines,the PD inception voltages of the coil were decreasing with the aging test.the impulse voltage insulation class and type of stator insulation system are determined by the qualification test.%高频冲击局部放电(PD)测试可以有效的检测电机绝缘系统的绝缘状态.根据传感器的不同,电机绝缘系统在高频冲击下PD测试方法主要有两种:高频电流传感器法和超高频天线法.试验表明:在高频冲击电压下,PD主要发生在冲击的上升沿和下降沿,在同一放电电压下,上升沿和下降沿的PD幅值较大;在风力发电机定子绝缘系统鉴别试验中,随着老化试验的进行,线圈的PD起始电压总体呈下降趋势.通过鉴别试验,可以确定绝缘系统的冲击电压绝缘等级及类型.